Corrosion rate estimations of microscale zerovalent iron particles via direct hydrogen production measurements

Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation

“…The use of mZVI rather than nZVI was preferred in this study due to the lower cost (1/20 to 1/3 compared to nZVI), lower corrosion rate (10 to 30 times lower than nZVI, (Velimirovic et al, 2014a)), and easier handling of microsized particles (provided as a dry powder). The design of this pilot test, and in general of any field-scale mZVI or nZVI delivery, is the result of the compromise among different, and often contrasting, needs: the slurry viscosity has to be sufficiently high to keep particles suspended until delivered into the porous medium, but sufficiently low to limit the injection pressure below or close to the critical pressure of the aquifer; the discharge rate is to be sufficiently low to limit the injection pressure, but sufficiently high to complete the delivery within the sedimentation time of the particles; the monitoring setup must allow a reliable, realtime control of all relevant parameters during injection (discharge rate, injected concentration, delivery pressure) and a cost-affordable but detailed reconstruction of the spatial distribution of the iron after injection, but must not interfere with the injection operations themselves.…”

Influences of nanoscale zero valent iron loadings and bicarbonate and calcium concentrations on hydrogen evolution in anaerobic column experiments

“…The initial H 2 generation led to the build-up of a gas phase in the column (approximately 8.7 mL (35% gas content) within 2 days) with corresponding rates of 4.4 mL/ d or 128 mmol H 2 /kg$d (11 g/kg nZVI on 120 g sand corresponds to 1.3 g nZVI). Velimirovic et al (2014) reported an initial H 2 evolution rate (first day) of Nanofer25S particles of Fig. 5 e Average H 2 generation rates as a function of the initial amount of Fe 0 in experiments with the particle products Nanofer25 and Nanofer25S and for different water matrices (data points are labeled in correspondence to Table 1).…”

Environmental application of millimeter-scale sponge iron (s-Fe0) particles (II): The effect of surface copper

“…The results proved that a Cu layer covering the surface favored the reactivity, but a too dense Cu layer decreased its reactivity severely [17]. Millimetric ZVI (mmZVI) and its bimetallic variants have attracted less attention owing to the weaker catalytic reactivity and the lower production of H 2 as the particle size of ZVI increases into the millimetre range [18]. As for mmZVI materials, few studies dealing with millimetric sponge iron (s-Fe 0 ) and its bimetallic variants have been published, although its advantages in the elimination of typical cationic triphenylmethane dyes had been demonstrated, including greater activity and stability, the potential utility of magnetic separation, and lower cost [19].…”